US4902487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of diesel exhaust gases
Assignee: Johnson Matthey Inc
•
Filing: 1988-05-13
•
Granted: 1990-02-20
•
Expires: 2008-05-13
Abstract
Abstract In a process wherein diesel exhaust gas is passed through a filter to remove particulate therefrom before discharge and particulate deposited on the filter is combusted, the improvement which comprises combusting the particulate with a gas containing NO 2 , which may be catalytically generated in the exhaust system.
Inventors
- 👤 Barry J. Cooper
- 👤 Hyun J. Jung
- 👤 James E. Thoss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:40
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/44; C09C1/48; C09C1/50; F; F01; F01N; F01N13/00; F01N13/009; F01N3/00; F01N3/02; F01N3/021; F01N3/023; F01N3/0231; F01N3/029; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2882; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; F01N2250/00; F01N2250/02; F01N2330/00; F01N2330/06; F01N2330/12; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
40 words
In a process wherein diesel exhaust gas is passed through a filter to remove particulate therefrom before discharge and particulate deposited on the filter is combusted, the improvement which comprises combusting the particulate with a gas containing NO 2 .
Claim 2
Dependent Claim
40 words
In a process wherein diesel exhaust gas is passed through a filter to remove particulate therefrom before discharge and particulate deposited on the filter is combusted, the improvement which comprises combusting the particulate with a gas containing NO 2 .
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the gas containing NO 2 also includes water vapor.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein the particulate is combusted at a temperature below 400° C.
Claim 5
Dependent Claim
32 words
The process of claim 3 wherein the gas containing NO 2 is provided by initially passing diesel exhaust gas containing NO over a catalyst to convert the NO to NO 2 .
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein the catalyst comprises a platinum group metal.
Claim 7
Dependent Claim
17 words
The process of claim 5 wherein the catalyst comprises a platinum group metal on a monolithic honeycomb.
Claim 8
Dependent Claim
15 words
The process of claim 6 wherein the filter includes a catalyst which facilitates particulate combustion.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein the filter catalyst comprises a base metal.
Claim 10
Dependent Claim
18 words
The process of claim 7 wherein the fliter catalyst comprises a combination of lanthanum, cesium and vanadium pentoxide.
References Cited (Backward Citations)
GB1014498A
Cited
US4303552A
Cited
US4451441A
Cited
US4516990A
Cited
US4670233A
Cited
GB2188559A
Cited
US4759918A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-19 | 1997-08-21 | 1998-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-19 | 2001-08-21 | 2002-02-20 | $7700.00 | Window Closed / Lapsed |